But here, in TSFS, she is credited simply as 'woman in cafeteria'. Although it is Grace Lee Whitney, there is no indication at all whether or not she is, in fact, playing Janice Rand.
I first met GLW at an Australian Trek convention not long after ST II came out. She was quite saddened not to have been asked back for ST II, but Rand was still aboard, as Transporter Chief, in Vonda McIntyre's novelization.
Having volunteered to collect GLW from Sydney's domestic terminal and escort her to the international terminal, I forged a bit of a connection and she invited me to visit her at work when I came to LA. At the time, her regular day job was at an actors' agency (its office had a creek-like water feature running through it!), and she looked after the likes of Ted Shackleford ("Knott's Landing") and soon-to-be-late Jon-Erik Hexum ("Voyagers!", "Cover Up").
When I arrived, in the January of 1984, filming of ST III had not long been completed and someone I met from the production mentioned in one breath that there was a secret cameo, and in a different breath mentioned having seen GLW at the wrap party!
When I caught up with GLW, I told her what I suspected and she was thrilled to be able to chat about her role, but that yes, it was still meant to be top secret, so I actually kept it quiet till preview night Down Under. It was a last-minute favour granted by Nimoy, and filming of the Spacedock Cafeteria scene was at ILM,
after principal photography had ended. So
yes, it's supposed to be Rand, but the uniform had commander rank on it. (She originally said it was "the same as Kirk's", so I almost expected they'd accidentally given her admiral or captain insignia.) GLW looked amazing and she was extremely happy with the scene; Robert Wise had ordered her to remove her glam makeup for TMP, and she'd been devastated how harshly the camera had treated her.
People will argue that it's not Rand in ST III, but the tears were meant to indicate that it was indeed Rand, watching her old, damaged home limp into dock.
Coincidentally, Rand and Chapel's sudden disappearance from the
Enterprise in the novelizations fits with the mention of
Firenz (in the ST II novelization) being sent to retrieve the injured cadets and take them back ahead of time for medical treatment.
Is there a reason she wasn't named as Rand?
Yes. It's a cameo. No lines to appear in the script. The scene wasn't even filmed until after principal photography ended. It was Directorial intention (ie. Nimoy) to make the character Rand.
INT. SPACEDOCK - THE CAFETERIA (FX SHOT WITH ILM 36 ELEMENTS) THROUGH THE WINDOW of a Spacedock facility, a few lounging Starfleet persons look up to see a memorable sight...
... battle-scarred Enterprise is passing alongside of the sleek Excelsior. Their size differential is apparent (B-29 to B-17). Yet, Enterprise carries with her a battle-scarred history of achievement. Some of the Starfleet people begin to rise, silently. A standing ovation for a hero's return.
In TVH, she wears a, erm, midshipman's uniform?
No, she doesn't. That character was not Rand.
Rand herself appears standing next to the 'table' with Pres. Roth and Adm. Cartwright, and is in an officer uniform, but she doesn't have any lines.
You are incorrect. She most definitely is in the jumpsuit and has scripted lines in ST IV, but they comprise background dialogue, and were included in appendices to to the main script.
She's in officer uniform in ST III (and ST VI and "Flashback"), but a jumpsuit in ST IV.
Here's a pic:
http://en.memory-alpha.org/wiki/Janice_Rand?file=Janice_Rand%252C_2286.jpg
Her character does appear briefly in the DC Comics that led up to the ST IV adaptation, and she's in an officer's uniform in those frames, as Cartwright's assistant.
Had I not seen publicity stills of her with the Vulcan salute from ST IV I probably would not have noticed her. I don't really think she was supposed to actually play Janice Rand, but it was a nice insider thing for the fans to notice.
Oh yes she was! And she and Majel Barrett even got together before their studio call and
rehearsed their lines together, because they knew they'd probably be little more than background players on the day of filming.
In "Starlog", GLW mentioned how they were trying to ascertain a rank to fit her ST IV outfit and insignia. She remembered being called "Chief" in TMP, so they settled on Chief Petty Officer for ST IV.